Fifth wheel wrecker hoist have been provided having a boom pivotally carried by the fifth wheel of a tractor and extending rearwardly thereof so as to be operated by cylinders carried by the frame of the tractor intermediate the ends of the boom. It was found necessary to provide adjustable means for securing the cylinders and the boom lifting or carrying sling with respect to the frame of the tractor which carries the fifth wheel. Depending upon the length of the frame it is desirable to facilitate adjustment between the boom and the fifth wheel so as to provide a pivotal connection at such a point that the boom will extend a desired distance rearwardly of the frame for supporting a load, such as a vehicle being towed by the tractor.
It is an important object of this invention that an adjustment means be provided for this purpose which is capable of ready adjustment but which will retain the boom positively in adjusted position during operation of the hoist.